title: Conformations of spermine in adenosine triphosphate complex: the structural basis for weak bimolecular interactions of major cellular electrolytes.
abstract: Selectively (2)H- and (13)C-labeled spermines (SPM) were efficiently synthesized and analyzed by NMR spectroscopy to determine the spin-spin coupling constants for six conformationally relevant bonds. SPM that is composed of three alkyl moieties, a butanylene, and two propanylene chains undergoes a conformational change when interacting with multivalent anions (e.g., adenosine triphosphate (ATP), ATP-Mg(2+) , and tripolyphosphate). Upon interaction with ATP, the C-C bonds, which affect the distance between the neighboring pairs of ammonium groups (i.e., N1/N5 and N5/N5'), increase the population of gauche rotamers by 17-20% relative to those in the 4 HCl salt of SPM. However, the trend in increments of the gauche conformers for the SPM-ATP complex profoundly differs from that of the spermidine (SPD)-ATP complex. This implies that SPM may preferentially recognize the adenyl group of ATP rather than the tripolyphosphate moiety. This may account for the higher affinity of SPM to ATP-Mg(2+) than with that of SPD, which chiefly interacts with β- and γ-phosphates and is easily replaced by Mg(2+) . These results may provide a clue for the further understanding of the structural basis of polyamine biological functions.
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka University, Machikaneyama, Toyonaka, Osaka 560-0043, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Maruyoshi
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Demura
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Matsumori
authors.forename: Tohru
authors.initials: T
authors.lastname: Oishi
authors.forename: Michio
authors.initials: M
authors.lastname: Murata
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry*; D006860:Hydrogen Bonding; D007553:Isotope Labeling; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D011073:Polyamines / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013096:Spermine / Q000737:chemistry*
chemical_list: D004573:Electrolytes; D011073:Polyamines; D000644:Quaternary Ammonium Compounds; D013096:Spermine; D000255:Adenosine Triphosphate